Process of making self-lubricating journals.



G. L. THOMPSON. V PROCESS OF MAKING SELF LUBRIGATING JOURNALS.

,1912. Patented Apr. 22, 1913.

UNITED STATES PATENT OFFICE.

GEORGE L. THOMPSON, 013 LOS ANGELES, CALIFORNIA.

PROCESS OF MAKING SELF-LUBRICATING JOURNALS.

Specification of Letters Patent.

Patented Apr. 22, 1913.

.- Application filed April 23, 1910, Serial No. 557,140. Renewed October 4, 1912. Serial No. 724,000.

To all whom it may concern:

Beit known that I Gnoncn L. Tnonrsox, a citizen,of the United States, residing at Los Angeles, in the county of Los Angeles aIid State of California, have invented certain new and useful Improvements in Processes of Making Self-Lubricating Journals,

ofwhich the following is a specification.

This invention relates to a new and improved process of making self-lubricating journals and refers more specifically to the production of journal bearings having 1ncorporated with one of the journal members one or more solid bodies of graphite.

1 Among the salient objects of the invention are to-provide a new and improved process of making a journal bearing having one or more bars or bar-like insets of solid graphite formed and exposed flush with the main- 9 bearing surface of the member and extendingftransversely of the direction of rubbing movement of the bearing surfaces; to providean improved process in which the preformed solid bar like insets form parts of the composite wearing surface of the memfber; to provide a method or process of man- -ufacture which insures that the exposed surface of the aphite will be exactly .fiush, true and uni orm with the remainder of the 3 bearing surface-10f the member,- and this without involving an expensive metal machining operation; to provide a process by which the graphite insets are so united with the remainder of the member as to remain fully efi'ective and efiicient during the whole life of the bearing; and in general to provideasimple and economical process of the character referred, to. v

The invention consists in the matters here- 40 inafter described, and more particularly 'for' casting' in' the metal which forms the chiefjjweaifrg fpart of the bearing; Fig. 2 '15 a perspective view of-the core shown in position in Fig-1; Fig.3 1s a view similar t Fi'g, 1 -showing. a modified construction;

omFigfe'isja cross-sectional view of the com-- pleted bearing'of which parts are shown in "Fig. 3 Fig. 5 is aperspective viewof one of'the-core segmen s shown in Fig. 3. Fig.

\ 6' is a'cross'sectional view of a divided box jogjournal member. 4 l

Numerous journal bearings and journal bearing members have heretofore been invented having graphite inserted in cavities or inset in the journal member, for the purpose of forming a self-lubricating journal or hearing. These prior art devices may be grouped into two classcs,-one in which the graphite is in the form of a semi-solid paste,

and the other in which the graphite is in opposed lubricated member soon empties the cavities or recesses'to a slight depth and thereafter fresh supplies of lubricant are only drawn out andbetween-the surfaces of the metal partsas the metalin which the graphite 1s inset:is actually worn away and the cavities thereby made shallower. This is, of course, a'serious defect and objection, since the lubrication does not continue fully efficient for any considerable length of time without renewal. g

The bearings of the second class referred to have two principal defects or objections,

viz: the tablet. or discontinuous form of the insets produces a more or less uneven distribution of the graphite, and it has been found impracticable if not impossible to cast the tablets in in such manner that their exposed surfaces will be fully and uniformlyfi'ush with the bearing surface of the metal, unless the wearing face of the metal be inachincd off after being cast-,iwhich involves an expensive operation. Moreover, the support upon which these tablets are preliminarily mounted is an item of considerable cost, must be made to proper' size for each different size of bearing and the operation of attaching the tablets to such support in itself involves a separate operation and considerable expense. V

' By my present invention I overcome the objections hereinbefore pointed gut. The invention as to both of its phases will be readily understood from thefollowing description, reference being had to the ac companying drawings.

A salient feature or characteristic of my improved process resides in pre-forming the graphite in such manner thato'neor more bar-like insets and core portions are combined in a single piece around which the molten metal which forms the chief part of the bearing member is cast. $ubsequently that part of the graphite which constitutes the core proper is cut away leaving the barlike insets finished and in position.

In formingbushings or sleeve-like bearing me'mbers of comparatively small diameters, I prefer to make the graphite cores solid with the bar-like insets integrally connected therewith as radial extensions. but where the bearing member is to be relatively large, as, tlor example, such a box or journal member as is commonly used for car jour nals, I prefer to make the core in the formof one or moreshell-like segments with which the insets proper are integrally formed. Describing, then. first the process and article as-matle in small sizes, and referringto Fig. 1, 6 designates a tubular metal jacket which ordinarily forms a permanent outer wall of the finished bearing sleeve or bushing. This tubular member 6 is cut to the proper length to form the desired bearing, and suitably arranged for casting moltenmetal therein. Conveniently the shell is stood upon one end, so that the metal may be poured into theopen upper end. Within the shell 6 is axially arranged a pre-formed graphite core member 7 provided with one or more-radial extensions 8 formed integrally therewith. These extcn sions 8 preferably extend the full length of the bushing shell. and are preferably slightly wedge-sha1nulin crass section with their smaller dimensions next to or connected with the core, so that when castiuto the metal of the lmshing the parts will be locked together by reason of their form. These graphite cores with their integral insets may be molded in a welt-understood manner from graphite in plastic form and under pressure, after which they are dried; the cores being so made as to be of hard consistenc and amply strong to act as cores around which the metal may be cast. llaring arranged theeore in proper axial position within the shell, I cast in molten metal 9 between the exterior oi the eylindric part of the core and the shell, thus surrounding the three exposed sides of the extensions 8. After the metal has solidified, the bushing is transferred to a suitable machine and the core part of the graphite bored out. Of course, in order to minimize expense of mamtfacturethe body of the core 7 will be made of the samesize, or substantially the same size as the journal for which the bushing is adapted, so that when the core has beenbored out the bushcore will be very slightly smaller than the size of the journal, so that .the interior of the bushing can be machined out ver slightly, tlms producing a perfectly true and smooth. bearing surface upon its interior. This boring out of the graphite core, and machining of the interior bushing, of course, dresses the. exposed surfaces of the insets S exactly flush with the remainder ofthe bearing surface of themember.

'here the journal member is of larger size, I prefer to make the graphite cores hollow, -so as to economize in the amount of graphite used in molding the core. Preferably the hollow core is made up of a plu rality of segments, as indicated at 10 (Fig.- 3) each segment being provided with an integral bar extension 8 substantially like the corres onding extensions 8 shown in Figs. 1 an 2. A set of segments which together form a complete-.cylindric shell is arranged tpncentrically within an outer metal shell 6. as in the previouslydescribed method, and,the metal 9' cast intci the space around such core. The space 1,1 within the core is, of course, left untitled in casting. After the metal has been cast into the bushing, the latter is bored or reamed out sub stantially as in the previously described construction: the only difi'erence being that it is only necessary to bore out the shell-like core inset ofa solid core. The finished journal member or bushing is shown in Fig. 4, and it is obvious that substantially the same construction will be produced whether the solid or hollow graphite core be used in forming it. e

While I have herein shown in both examples journal bearing members which are complete eylindrie bushings. it is. of course. obvious that substantially the same method of procedure can be followed in producing a half box or other segmental bearing member,

such for example as hat shown in Fig. 6.

'.\0 departure from the method is made -when the outer shell or mold within which porarily for this purpose and does not becoinea permanent part of the bearing member, and this is truewhether forming com-- plete cylindric beurings'or segments only.

. I claim as myinvention:

1. The herein describedmethod of making composite self-lubricating journal members, which eonsistsin first forming acore memher with one 0121 1991? integral rib projections the wearing metal is cast is used only temof graphite, next arranging said core meal-- her in proper-rem ion to a nioldand with its rib projections extending into the mold space, then casting molten metal within said mold space and around said rib projections,

With reference to an outer mold shell, then the core and mold shell and around the rib projections, and finally machining out the graphite core proper, leaving the graphite rib members in the form of bar-like inserts embedded Within the cast metal and surjtaced flush with the bearing surface of the metal.

and finally, after the metal has solidified, removing the core portion proper, leaving the rib projections embedded in the metal I and flush With the bearing surtaee thereof.

2. The herein described method of makin composite self-lubricating journal members, which consists in first pro-forming a core of graphite'provi(led with one or more integral radially projecting and longituoinally Eli-I GEORGE L THOMPSON; \Vitnesses CHAS. S. BROWN,

ALBERT H. GRAVES.

tendingribs, arranging said core axially casting molten metal into the space between 

